1. Field of the Invention
The present invention relates generally to a storage apparatus for optically recording and regenerating information on an optical storage medium by use of a laser light, and more particularly, to a storage apparatus for executing the recording or regeneration while determining the optimum laser power of a laser diode by test recording on the medium upon the reception of a host command.
2. Description of the Related Arts
An optical disk apparatus is widely known as an optical storage that serves as a data storage unit for performing recording and regeneration by use of an optical storage medium and a head. To keep the recording and regeneration performances of the optical disk medium such as a magneto-optical disk in the optical disk apparatus, the optimum laser power of the laser diode needs to be determined. Data recording is typically carried out by a preset write laser power (default write power) proper to the apparatus, depending on radial locations on the data recording optical disk medium and depending on apparatus temperature. With the increased recording density of the optical storage medium, however, it is getting difficult to achieve an optimum recording by the write laser power proper to the apparatus. As a solution to this problem, test recording (test write) is performed to determine the optimum laser power previous to the data recording. In the test recording, previous to the data recording the data are erased and recorded in a test recording region in the vicinity of the data recording region by the default write laser power, after which the error correction function is cancelled for regeneration and the write data and the regeneration data are compared with each other to figure out the error data count of the data. Such test recording is iterated by a prescribed number of times while varying the recording laser power. As a result of this, a point minimizing the read error data count is determined as the optimum laser power for recording. The test recording induces an extended operation time due to the iteration of the erase, recording and regeneration with the varying recording laser power. In the event of incapability of finding the optimum laser power with the variances of the power value by the prescribed number of times in particular, a retry is needed for finding the optimum laser power with a further variance of the recording laser power, which may further take an additional operation time. In this manner, the test recording is time-consuming, during which the write command must be stood by. Too a long standby of the host may result in an impairment of the apparatus recording performances, and even longer standby may possibly cause a timeout error and hence an apparatus recording failure. In order to prevent such a performance degradation arising from the test recording, the inventors of this application have proposed a method in which the test recording is executed in a separate manner (U.S. Pat. No. 6,014,349). In this separate test recording, the test recording executed in response to a command from the host is once interrupted at the elapse of a certain period of time to perform the host command processing and is resumed from the last interrupted sequence at the issuance of the next host command. By the way, the laser power optimum recording conditions vary depending on the radial locations on the optical recording medium, so that the medium is segmented into a plurality test recording effective areas in the radial direction of the medium so as to ensure that the recording within each area can be made under the same conditions. This means that the result of a test recording of a certain area is effective only in the area where the test recording has been made and that for the recording in a different area another test recording for obtaining the optimum recording conditions in the different area must be executed.
In recent years, application of the optical storage apparatus to the multimedia adapted data processing system necessitates the recording and regeneration of sequential data such as acoustic data or animation data. In case of recording the acoustic data, it is preferred to record the acoustic data on the optical disk medium in a sequential manner since the acoustic data or the animation data are typically sequential data. Thus, sequential data recording is made. From their characteristics, the acoustic data or the animation data must be recorded in a sequential manner. Therefore, if the recording processing is interrupted for a long period of time, it may become difficult to process the subsequent data in sequence, resulting in errors. In this manner, it is preferred for the sequential recording of the acoustic data or the animation data to minimize the interruption. In case of using the optical disk apparatus for the acoustic data recording purposes for example, from the feature of the acoustic data recording a method may often be employed in which data are sequentially recorded on a spirally extending track of the optical disk medium. More specifically, sequential recording is effected from the innermost or outermost track and, the instant that recording is complete of the entirety of a certain area where the optimum laser power has been determined, the recording of the next area is started. In cases where a migration occurs to the next area beyond the current area where the test recording result is effective as a result of such sequential data recording, write processing in the next area cannot be performed till that time, so that the test recording must again be carried out due to the indetermination of the optimum laser power. However, in the event of the execution of the sequential recording of the sequential data such as acoustic data, the test recording processing takes place at the time of change of the area resulting in the effective range of the optimum laser power determined by the test recording. Therefore, a longer time is required to issue a completion report after the reception of a write command from the host, making it difficult for the sequential data to stand by too long, which may possibly result in host recording errors.
According to the present invention there is provided a storage apparatus capable of preventing any interruption or delay of processing attributable to the test recording upon the area change in the recording of sequential data beyond the effective range area of the optimum laser power determined by the test recording.
The storage apparatus of the present invention comprises an optimum condition setting processing unit and a setting unit. The optimum condition setting processing unit divides a medium into a plurality of optimum condition effective areas and determines optimum conditions used in recording or regeneration in each of the plurality of areas. The setting control unit, when judging a possibility of a migration to an adjacent area, provides a control of the optimum condition setting processing unit so that the optimum conditions for use in the adjacent area are determined in advance. More specifically, for each of a plurality of optimum condition effective areas of a medium segmented in a predetermined direction of the medium, the optimum condition setting processing unit performs optimum condition setting processing on the medium to determine optimum conditions used in recording or regeneration in each area. When during the recording or regeneration of data in an optimum condition effective area, a migration is judged- of data recording or regeneration to an adjacent next optimum condition effective area, the setting control unit provides a control of the optimum condition setting processing unit to allow execution of the optimum condition setting processing of the next optimum condition effective area so that the optimum conditions are determined in advance. As used herein, the optimum condition setting processing includes setting an optimum power of a light beam emission power for any one of recording, regeneration and erase for example or includes setting an optimum magnetic field. The setting control unit allows a separate execution of the optimum condition setting processing of the next optimum condition effective area. For the determination of e.g., the laser power as the optimum condition to be performed at every change of the optimum condition effective area on the medium, a lot of time is required due to plural-times repetition of the erase, recording and regeneration. Hence, in the present invention, when coming closer to the next optimum condition effective area, the next optimum condition setting processing is executed in a separate manner so that the optimum laser power is determined in advance before entering the next area, thereby obviating the delay or interruption of the processing of sequential data.
In synchronism with the reception of a command by a predetermined number of times from a host, the setting control unit allows a separate execution of the optimum condition setting processing of the next test recording effective area. For example, at every time the write command of recording of the sequential data is received 100 times, the optimum condition setting processing is separately executed so as to disperse the delay of the command processing attributable to the separate processing of the test recording performed previous to the write command, to thereby relieve the influence. The setting control unit makes a judgment of being processing of sequential data when recording or regeneration target blocks are substantially continuous along a track of the medium. More specifically, the setting control unit makes a judgment of being processing of sequential data when relative to a last track for the most recent recording or regeneration, a leading track for the current recording or regeneration lies within a prescribed number of tracks and when this continues over a prescribed number of times. In this case, the optimum condition effective area is composed of a single zone or a plurality of zones. The zone is a zone (ZCAV) or band that is recorded or regenerated with a constant angular velocity. In cases where the test recording effective area of the optical disk is composed of a single zone or a plurality of zones, the setting control unit makes a prediction and judgment of a migration of continuous recording or regeneration to the next test recording effective area when recording or regeneration of the sequential data migrates to a zone adjacent anteriorly to the next test recording effective area. More specifically, it makes a prediction and judgment of a migration of continuous recording or regeneration to the next test recording effective area when the sequential data recording or regeneration migrates to the latter half of a zone adjacent anteriorly to the next test recording effective area.
The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.